The rise in technology has led to greater sophistication in the field of document authentication. Document features, such as inks, holograms, vignette windows, security threads, etc., are being increasingly used to decrease the likelihood of counterfeiting. For example, special inks, which may be applied to currency, may have a unique spectral profile that is difficult to mimic without access to sophisticated knowledge and technology, thereby decreasing the likelihood of counterfeiters copying and applying these inks to counterfeit currency. As document authentication features have become more sophisticated, a need has arisen for new methods of authenticating these and other features.